Removing
Remove cylinder head (see section "Removal and installation of cylinder heads").
Attention! Old valves must be installed in their original places. Mark all valves before disassembly. After prolonged operation of the engine, a burr may form on the contact surface of the crackers with the valve stem. It must be removed with a velvet file so that the burr does not leave scratches when passing through the valve guide.
Press down on the plates of the valve springs and remove the crackers. In workshops, a clamping device is used for this purpose (see picture) or valve spring compressor (see chapter "Tools"). The valve spring plate can also be pressed down with two sturdy screwdrivers. Then (any way you press) insert a foot into the combustion chamber so that the valve does not fail when pressed. In this case, the assistant must take out the crackers.
To take out a plate of a spring, a valve spring and a cuff. Examination
Clean the disassembled valves with a wire brush.
Check the valves for carbon deposits on the seats, runout and signs of wear of the rods, as well as damage to the cracker grooves.
Attention! The valve stem must not be machined or straightened. Damaged valves must be replaced.
If only the end surface of the rod is broken, then only the valve cuff can be replaced. Cuffs are available at the service station VW / Audi (catalog number - 113 109 621).
The cuff is put on the valve stem before installing the rocker arm and does not require additional locking.
Installation
Before installing the valves, in this case, the following work must be carried out: check the valves and their guide bushings in the cylinder head, grind the valve seats in the cylinder head, grind and grind the valves, check their seats for tightness.
Apply a layer of paste based on M0S2 to the valve stems, install the valves in their original places in accordance with the marks.
Install new seals on the valve stems.
Install valve springs and spring plates.
Attention! Install the valve springs in such a way that the coils with a smaller pitch are directed towards the cylinder head.
Compress the springs with a suitable tool and install the cotters.
Instruction. The run-in crackers must be ground on the parting surface to such an extent that the valve stem can be rotated in them.
Visitor comments